Problem: Which of these numbers is composite? ${37,\ 41,\ 43,\ 44,\ 71}$
Solution: A composite number is a number that has more than two factors (including 1 and itself). 37, 41, 43, and 71 each have only two factors. The factors of 44 are 1, 2, 4, 11, 22, and 44. Thus, 44 is the composite number.